content: /*
   * Copyright 2016-present David Karnok
   *
   * Licensed under the Apache License, Version 2.0 (the "License");
   * you may not use this file except in compliance with the License.
   * You may obtain a copy of the License at
   *
   *     http://www.apache.org/licenses/LICENSE-2.0
   *
   * Unless required by applicable law or agreed to in writing, software
   * distributed under the License is distributed on an "AS IS" BASIS,
   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
   * See the License for the specific language governing permissions and
   * limitations under the License.
   */
  
  package hu.akarnokd.rxjava3.operators;
  
  import java.util.*;
  
  import org.reactivestreams.*;
  
  import io.reactivex.rxjava3.core.Flowable;
  import io.reactivex.rxjava3.exceptions.Exceptions;
  import io.reactivex.rxjava3.internal.subscriptions.EmptySubscription;
  
  /**
   * Merges a fixed set of sources by picking the next smallest
   * available element from any of the sources based on a comparator.
   * 
   * @param <T> the source value types
   * 
   * @since 0.8.0
   */
  final class FlowableOrderedMerge<T> extends Flowable<T> {
  
      final Publisher<T>[] sources;
  
      final Iterable<? extends Publisher<T>> sourcesIterable;
  
      final Comparator<? super T> comparator;
  
      final boolean delayErrors;
  
      final int prefetch;
  
      FlowableOrderedMerge(Publisher<T>[] sources, Iterable<? extends Publisher<T>> sourcesIterable,
              Comparator<? super T> comparator,
              boolean delayErrors, int prefetch) {
          this.sources = sources;
          this.sourcesIterable = sourcesIterable;
          this.comparator = comparator;
          this.delayErrors = delayErrors;
          this.prefetch = prefetch;
      }
  
      @SuppressWarnings("unchecked")
      @Override
      protected void subscribeActual(Subscriber<? super T> s) {
          Publisher<T>[] array = sources;
          int n;
  
          if (array == null) {
              array = new Publisher[8];
              n = 0;
              try {
                  for (Publisher<T> p : sourcesIterable) {
                      if (n == array.length) {
                          array = Arrays.copyOf(array, n << 1);
                      }
                      array[n++] = Objects.requireNonNull(p, "a source is null");
                  }
              } catch (Throwable ex) {
                  Exceptions.throwIfFatal(ex);
                  EmptySubscription.error(ex, s);
                  return;
              }
          } else {
              n = array.length;
          }
  
          if (n == 0) {
              EmptySubscription.complete(s);
              return;
          }
  
          if (n == 1) {
              array[0].subscribe(s);
              return;
          }
  
          BasicMergeSubscription<T> parent = new BasicMergeSubscription<>(s, comparator, n, prefetch, delayErrors);
          s.onSubscribe(parent);
          parent.subscribe(array, n);
      }
  }
  